docs: def from_json(stream, cls=None, object_pairs_hook=OrderedDict, **extras):
      """
      Convert a JSON string or stream into specified class.
      """
      stream = stream.read() if hasattr(stream, 'read') else stream
      json_dict = json.loads(stream, object_pairs_hook=object_pairs_hook)
      if extras:
          json_dict.update(extras)  # pragma: no cover
      return to_model(cls, json_dict) if cls else json_dict